Do you have Burials for Richard/Elizabeth?
Is that how you have a possible age for him?
What confirmed Baptisms of Children do you have?
Or at least the Child of theirs you are decended from please.
This all I can find at present;
Christenenings, Crowland Abbey to RICHARD/ELIZ
MARY Craxford 29 Jan 1756 to Richd/Eliz (buried April 1756, St Guthlac)
ELIZ Craxford 11 Sept 1760 to Richard/Eliz
MARY-ANNE Croxford 05 Sept 1764 to Richd/Eliz
MARY 30 April 1769 to Richard/Elizabeth
There is a MARY Croxford buried St Guthlac 27 March 1769, Daug Richard/Eizabeth so looks like the baby on the way was named after her April 1769.
(Source FreeREG)
Familysearch.Org has this Child also;
GREEN Croxford, 30 Jan 1762 to RICHD/ELIZ
Possible Marriage;
Richard CROXFORD of Crowland Parish to Eliz GREEN of Crowland Parish
09 July 1755, St Guthlac, Crowland, Lincolnshire
Witnesses, James GREEN, Wm BECKWITH
Trish
